[steve25]

Yes your statement is true.

[Skip Fix]

Originally Posted by steve25

Yes your statement is true.

What that a 215 cc port on a 455 will be lazy?

And what size are SBC 350 Vortec TRUCK heads in relation? 185cc! 327 461s-161-172! Smaller motors the Vortec truck heads larger the 461X at 172 larger than most D ports. My Vortec headed truck hauled my trailer and 3900 lb TA form Houston to Memphos and Atlanta ! Truck was 5575 when I rolled it on the scales at one track.

Wonder what size the 5.3 LS motor on my wife's Avalanche that hauled her horse trailer and 1200 lb horse!

[Steve C.]

This reminds me of a statement made by a well known Pontiac persoality in our community, during a discussion about the HUGE ports when the Edelbrock head first came out.
He was running 11.76 et with mild ported factory heads and a 234 degree HFT cam at the time.

His comment..

"I do need a set of E heads so I can run a 4000 stall converter, 4.10's, more cam and wind it 6500 to run what I do now!"



.

[Formulajones]

Huge ports, hahaha

[p4msi1]

I don't know what all the fuss is about using a big port on the street. Most of us have 455ci+ engines. I just built a .060 + 455 for my son-in-law with 360cfm Edelbrocks. They are ported pretty big but show no signs of being sluggish at low rpm. It also fries the tires at 50 MPH in 2nd gear with 3.08 rear gears. I don't think iron heads can compare.

[Formulajones]

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

[PAUL K]

Originally Posted by Formulajones

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

What did that car run in the 1/4?

Recall the sixty foot?

[Jay S]

Originally Posted by Formulajones

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

That is interesting, what was the peak power at 5800? A 455 using 330 cfm running about 104% VE should carry a 455 past 7000. Seems like with that much cam it should have carried the power longer? Are those the same heads that are on your dads car now the big engine?

[Skip Fix]

My pump gas motor in the 78 TA has KRE 320 cfm CNC heads on it and a 239/247 @ 0.050 and has lots of bottom end with the Continental convertor. And has run 10.90s @124 in good air!

[Jay S]

It also made a difference what the heads flow at different valve lifts, not just the peak flow. I have seen plenty of flow bench tests that didn’t test below .2”, which make no sense to me because below .2” is where all the cylinder scavenging happens. Better low lift flows generally result in less low end power but more mid range, and pull the power peak back some.

[Stan Weiss]

Originally Posted by Jay S

It also made a difference what the heads flow at different valve lifts, not just the peak flow. I have seen plenty of flow bench tests that didn’t test below .2”, which make no sense to me because below .2” is where all the cylinder scavenging happens. Better low lift flows generally result in less low end power but more mid range, and pull the power peak back some.

Jay,
Time is money. So less testing at less lift points is cheaper. I know that David Vizard like to start testing @ 0.050" lift and does every 0.050" until around .400" and the goes by .100" increments

Stan